For each normalization strategy, five point selection strategies are considered to identify a set of \(n\)  pairs of 3D points \((p_1,p_2)\) , \(p_i=\lbrace x_i,y_i,z_i\rbrace \)  for binary comparisons. Four of these were described in the 2D descriptor context [1]}, and a novel fifth method is investigated here (shown as method 4 below). These are illustrated in 2D \(x,y\)  coordinates in Figure REF :
